Impact operated switch



March 17, 1953 Ni. BRADNR 2,632,069

IMPACT OPERATED SWITCH Filed Jan. 16, 1950 f M5210-A BRADNER Patented Mar. 17, 1953 UNITED STATES PATENT OFFICE IMPACT OPERATED SWITCH Mead Bradner,

Foxboro,

Mass., assignor, by

mesne assignments, to the United States of America, as represented by the Secretary of the Navy Application January 16,1950, Serial'No. 138,740V

The present invention relates to electric switch actuating means and more particularly to electric switch actuating means whereby circuits may be operated when disposed in sealed or inaccessible locations.

When switch mechanisms are disposed in inaccessible locations such as within uid tight bodies or the like, means must be provided for actuating the switch at the desired time. For example, in some types of naval torpedoes it is desired that the tubes comprising a part of the control mechanism be preheated prior to launching so that the control mechanism will be in condition to operate properly during and after the launching process. I'his is accomplished by means of a separate lilament heater circuit which is kept separate from themain control circuit so that theenergy of the batteries operating the latter will not be dcpleted. The above circuits are enclosed within the torpedo and hence normally are inaccessible. i

The present invention is particularly adapted for use in such installations since a simple hammer blow or the like on vthe side vof the torpedo will suflice to actuate the control switch and energize the circuit.

Heretofore the operation of such circuits has lf' switch actuating means of the present invention' need not be confined to operatingY circuits disposed in inaccessible locations but said means may be employed in any situation wherein circuit making or breaking operations must be per` formed.

An object of the present invention is to provide a novel means for actuating electric switches.

Another object is to provide means for actuating electric switches disposed in inaccessible 1ocations.

Yet another object of the invention is to provide means for establishing a circuit disposed in an inaccessible location and having in combination therewith time delay means for interrupting' the circuit. l A

Still another object of the invention is to provide a circuit maker and breaker which may be disposed on one side of a wall and be actuated byrmeans of a blow applied to the other side ofi e5 said wall.

8 Claims. (Cl. 20G-52) of the present invention.

A still further object of the invention is to provide a circuitcontrolling device for underwater ordnance which may be actuated prior to launching of the torpedo so as to make a circuit but which will automatically act to interrupt the circuit after a certain delay. i

Other objects and their attendant advantages will become apparent as the following detailed description is read in conjunction with the accompanying drawing wherein:

Fig. 1 is a sectional side view partly in elevation of one embodiment of the present invention; and

Fig. 2 is a diagrammatic representation of a circuit employing electric switch actuating means In the embodiment illustrated, the switch actuating means Il comprises a hollow container I`I welded or otherwise rigidly secured so as to abut the inner surface of a wall I2 of a sealed body such asa naval torpedo. The bottom I3 of the container is suitably apertured at hi to admit electrical leads I5 and I6 to the interior of the container. Floating within the container I l on springs I'I and I8 is a large sleeve i9 which supports a shaft 2D upon which is mounted an inertia bar 20 having masses 2l and 22 of substantially equal weight on opposite ends thereof. The bar 2|] is biased at one end by means'of a rectractile spring 23 so that the mass 2| normally abuts an anvil 24 integral Withth'e top of the container l l and contiguouswith the shell l2 of the sealed body as shown. One end of the bar Ztl bears an electric contact element 26 positioned toengage a mating contact element 21 secured on a bracket' 2'Ia whenever inertia bar 20 is actuated.

"A circuit'through contactsAZG and 2l is closed at'the appropriate time by means of a light blow, as would be imparted by the small mallet 25 shown, on the sealed bodyidirectly over the'anvl 24. The impact of this blowimpart's sufcient kinetic energy through shell |2` and anvil 24 to the mass 2l to overcome the inertia of the bar 20 and cause it to rotate about point 2B' in a counterclockwise direction.

If desired the circuit/may thereafter instantaneously be broken by the rectractile spring 23 which tends Ato return the parts to circuit open position. However, in the event that it may be desired to hold the circuit closed for a short period of time means maybe employed for that purpose. Forexample, a circuit may be used in a naval torpedo as illustrated in Fig. 2 wherein is provided a relay 3!) which when energized closesa switch 3| and thereby completes a iilament circuit 36. Latch" 32 serves to lock the switch 3l in on position andthereafter current from battery 4I serves to heat parallel laments 42, 43 and M. Switch contacts 26 and 2'! must remain engaged a sunicient length of time to assure proper operation of the relay 3S and locking engagement of latch 32 to retain the switch in its closed position. This may be assured by the provision of a time delay mechanism t cooperate with the inertia bar 20. Such a mechanism is illustrated in Fig. 1 and comprises a ratchet wheel 33 freely rotatable on shaft 20 and engageable by .pawls 34 and 35 on the bar 2B when it is moved in a circuit breaking direction by the retractile spring 23. Rotatable with said ratchet is a spur gear 3l which meshes with a second spur gear 38 affixed to an escapement ratchet 39. An oscillating pawl -t limits the speed of rotation of escapement ratchet in the usual manner and the period of oscillation of the pawl 450 determines the speed with which the switch contact elements 2t and 27 disengage after engaging. It will be apparent that the delay period may be varied by the provision of an oscillating pawl having different oscillating characteristics as S well known in the art, or the delay period may be changed by providing a train of any number of suitable gears between the oscillating .pawl di) and the ratchet 33 that will give the desired delay. Obviously, any movement delaying means such as a fan governor, inertia wheel or the like, may be substituted for the escapement ratchet and oscillating pawl. I

In the operation of the circuit of Fig. 2 it will be apparent that Ythe lament heater circuit may be established by a simple hammer blow at a selected spot on the outside of a torpedo. This circuit is established by the use 'of an electrically operated relay and suitable mechanical latching means is provided to retain the relay in actuated position after it is energized. Because of the time delay escapement arrangement the load al1- plied to battery 45 is only of short duration and its power is therefore not depleted for its intended use elsewhere by means of connections A-A. It will be apparent, of course, that by varying lthe strength of the mallet blow it will be possible to vary the time interval with which the contacts 26 and 2l remain in engagement. A light blow, for example, will cause only a slight rotation of the bar 20 Vin order that only the end portions of the contacts engage so that the circuit thus will be interrupted after a correspondingly shorter period of time.

It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention and that numerous modifications or alterations may be made therein without departing from the spirit and scope of the invention as set forth in the appended claims.

What is claimed is:

l. Electric switch actuating means whereby a switch may be operated by an impact to rst establish and after a delay linterrupt the circuit comprising; an anvil portion accessible to receive an impact, an inertia member vresiliently urged v said inertia member when the anvil receives a blow and thereafter releasable from set position by said retractile means acting upon said inertia member.

3. Electric switch actuating means whereby a switch may be operated by an impact to close a circuit and after a period of delay automatically interrupt the circuit comprising; an anvil portion positioned to receive an impact, a balanced inertia member pivoted about its center of gravity and having one end resiliently urged against the anvil portion and movable therefrom upon an impact blow against the anvil, switch means for closing an electric circuitupon movement of said balanced inertia member, retractile means for moving the switch means in a circuit breaking direction upon closing of the electric circuit, time delay means cooperating with said switch means whereby the circuit is interrupted after a period of delay, said time delay means comprising a ratchet movable when the switch means is moved in a circuit breaking direction, a gear train cooperating with said ratchet, and means Iconnected with said gear train for delaying movement thereof whereby the opening of the switch means is delayed when it is moved in a circuit breaking direction by the retractile means.

4. An impact operated switch for closing an electric circuit comprising an anvil, a centrally pivoted arm, masses of equal weight at the opposite ends of the arm, one of the masses being normally urged against one side of the anvil so that a blow applied to the other side of the anvil will move therefrom the mass in contact therewith, an electric contact on the arm, and an electric contact spaced therefrom, the con tacts being engaged to close the electric circuit upon movement of the arm by the impact of a blow imparted to the anvil.

5. An impact operated switch for closing an electric circuit comprising a housing, an anvil in one side of the housing, an inertia arm pivoted in the housing about its center of gravity and having one end normally urged against the inner side of the anvil, an electriccontact on the arm, a mating electric contact spaced therefrom, the contacts being engaged to close the electric circuit upon movement of the arm by an impact. on the outer side of the anvil,

6. An impact operated switch for closing an electric circuit in a sealed body comprising an impact reeciving surface on the exterior of the body, a centrally pivoted arm within the body, masses of equal weight at the opposite ends of the arm, one of the masses being normally urged against the inner side of the body adjacent the impact receiving surface thereof, an electric contact on the arm, a fixed electric contact spaced therefrom, the contacts being engaged to close the electric circuit upon movement of the arm by impact of a blow imparted to the exterior impact receiving surface of the body.

7. An impact operated switch for closing an electric circuit comprising a housing, an anvil forming a part of the housing, a centrally pivoted arm within the housing, masses of equal weight at opposite ends of the arm, resilient means engaging both the housing and the arm for normally urging one of the masses against the anvil, an electric contact on the arm, a mating electric contact spaced therefrom, the contacts being engaged to close the electric circuit upon movement of the arm by impact of a blow imparting means to the anvil, said resilient means thereafter returning the arm toward its initial position, and time delay means to control the return movement of the arm whereby the circuit is interrupted after a predetermined time interval.

8. An impact actuated switch for an electrical circuit comprising a housing, an anvil mounted on said housing, a centrally pivoted arm, masses of equal weight on opposite ends of the arm, a coil spring to urge one of the masses into engagement with one side of the anvil so that a blow applied on the opposite side of the anvil will cause the mass to move away from said anvil, an electric contact mounted on said arm adjacent said anvil contacting mass, a mating contact spaced therefrom and mounted on the housing, said 15 contact being engaged to close the electrical circuit upon movement of the arm resulting from the impact of a blow struck on the anvil, said spring thereafter urging the arm toward its initial position, and a time delay means to control the return movement of the arm whereby the circuit is interrupted after a predetermined time interval.

MEAD BRADNER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,542,635 Nyman June 16, 1925 1,844,331 Myers Feb. 9, 1932 2,185,732 Huelsdonk Jan. 2, 1940 FOREIGN PATENTS Number Country Date 188,430 Great Britain Nov. 16, 1922 259,938 Switzerland July 1, 1949 

